Well-aligned and highly ordered architectures are always required in many fields, such as tissue engineering, electronics, and preparation of composite materials. In this study, electrospun mats with well-aligned fibers and various fiber assemblies were successfully fabricated by electrospinning of poly(vinylbutyral) (PVB)/inorganic salt solution under the optimal salt condition. Then, the effect of inorganic salts on the degree of electrospun fiber alignment was comprehensively investigated, and the results indicated that the viscosity and conductivity of the solutions were the key factors influencing the degree of fiber alignment. It was expected that this simple and feasible method could be helpful for the fabrication of the well-aligned electrospun fibers and various fiber assemblies. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1047-1052, 2011